Visibility Issue Involving Water

I'm working on a map called ctf_submerged_eden. It has sort of an atlantis-like theme, but also has mechanical parts. This is gonna be my first TF2 map, and Source map in general.

Now, with that out of the way, I'd like to ask your advice about a problem I'm having. It all started when I func_detailed an octagonal platform that surrounds a column of water (which acts as an elevator of sorts). When I func_detailed it (in order to cut compile time down, since vvis was hanging), I noticed this weird graphical effect happened.

Needless to say, I thought it was fugly, so I removed the func_detail. However, the effect stayed. I've tried everything from remaking the platform, remaking the column of water, and copy/pasting the whole map into a new file. Nothing has gotten rid of this annoying graphical glitch.

Please tell me if you know what's causing the problem, and tell me how I could fix it. Thanks.